This paper studies the effect of contact areas on the transient response of mechanical structures. Precisely, it investigates replacing the ordinary beam of a structure by two beams of half the thickness, which are joined by bolts. The response of these beams is controlled by adjusting the tightening of the connecting bolts and hence changing the magnitude of the induced frictional force between the two beams which affect the beams damping capacity. A cantilever of two beams joined together by bolts has been investigated numerically and experimentally. The numerical analysis was performed using ANSYS-Workbench version 17.2. A good agreement between the numerical and experimental results has been obtained. In general, results showed that the two beams vibrate independently when the bolts were loosed and the structure stiffness is about 20 N/m and the damping ratio is about 0.008. With increasing the bolts tightening, the stiffness and the damping ratio of the structure were also increased till they reach their maximum values when the tightening force equals to 8330 N, where the structure now has stiffness equals to 88 N/m and the damping ratio is about 0.062. Beyond this force value, increasing the bolts tightening has no effect on stiffness of the structure while the damping ratio is decreased until it returned to 0.008 when the bolts tightening becomes immense and the beams behave as one beam of double thickness.
The purpose of this research is to highlight the nature of the relationship between the mental abilities of decision makers and strategic orientation . The intellectual capacity of decision-makers is the cornerstone for the implementation of all the tasks and duties of the Organization and constitutes the most important of its capabilities. As a result of the sharp changes in the environment in which it operates, this organization must accurately define its strategic directions to ensure its
survival and continuity. The problem of field research was to answer a fundamental question: Is the Iraqi director aware of how to employ mental abilities in strategic direc
... Show MoreIn the marsh of the vast technical development and its reflections on the public life in all of its forms man lives in the shade of this and that and he is in a disprate need to took attentively at his reality through a new artistic vision which the imagination gives it , its value, from this point we find the designers pay great efforts in creating advertising designs that creation and fertile imagination are consisting one unit, and through her flying study on the reality of employing the creative imagination in the designing of printed advertisements, the researcher submitted her questions where some of which are: -What are the requirements of employing the creative imagination in the designing process? And -What are the machineries o
... Show MoreThe research problem is that the traditional methods of internal auditing are somewhat heavy with long and rigid procedures for the members of the audit process team, especially in light of the current developments that are reflected in the business environment and internal audit reports, so it is necessary to reconsider the traditional internal audit work method and assess the extent of its development by agile methods to reduce the time of the audit process on the activities and elements that add value and direct the effort and time to the activities and elements that add value to the work of the economic unit and the report of the internal auditor.
The research aims to study the possibility of applying agile internal auditing
... Show MoreBackground: Cervical lymph nodes are prone to involved by a number of pathologic processes. They are common sites for lymphoma, metastasis, and reactive enlargement in a number of conditions. Aims of the study:-Clinical evaluation of patients with cervical lymphadenopathy. Differentiation between benign and malignant lymph nodes by means of ultra sounds (US) and Correlate the US findings with cytological and/or histopathological findings of cervical lymph nodes. Subjects, Materials and Methods:-The present study was carried out over a period of 6 months and included 81 patients of different age groups presenting with cervical lymphadenopathy. Each patient was examined clinically, then comprehensive sonographic examination of the neck for
... Show MoreMedina was according to its importance and religious status the basis for the emergence and emergence of historical schools, it is the emigration of the Prophet and the presence of the companions , and it was natural to shine the beginnings of historical codification, whether in the process of collecting and codification of the verses of the Koran or the Hadith, and once the pillars settled Islam in the Islamic areas until the Muslims began to go to the city to provide a broader knowledge of the Islamic religion and everything related to the biography of the Prophet and the significance and actions, and in return took the jurists and preservation and readers of the companions and followers to undertake the task of teaching in work
... Show Moreمدة تولي رئاسة السلطة في الفكر السياسي الاسلامي المعاصر
Wrong behavioral deviations among youth witnessed an obvious growing, some of these deviations are, robbery, drug and internet addiction, and smoking. Additionally, intellectual extremism and the disrespect of the traditions and genuine customs, In light of this issue, the research aims to shed light on the educational and preventative role of the woman in protecting and immunizing children from the wrong behavioral deviations. The woman has a significant and influential role in the society in general and in her family, in particular to the responsibility lies on her. The research shed light on the manifestations of behavioral deviation in children and the mechanisms of prevention and treatment. The research concluded with a set of recom
... Show MoreChest X-rays have long been used to diagnose pneumothorax. In trauma patients, chest ultrasonography combined with chest CT may be a safer, faster, and more accurate approach. This could lead to better and quicker management of traumatic pneumothorax, as well as enhanced patient safety and clinical results.
The purpose of this study was to assess the efficacy and utility of bedside US chest in identifying traumatic pneumothorax and also its capacity to estimate the extent of the lesion in comparison to the gold standard modality chest computed tomography.
This paper presents a statistical study for a suitable distribution of rainfall in the provinces of Iraq
Using two types of distributions for the period (2005-2015). The researcher suggested log normal distribution, Mixed exponential distribution of each rovince were tested with the distributions to determine the optimal distribution of rainfall in Iraq. The distribution will be selected on the basis of minimum standards produced some goodness of fit tests, which are to determine
Akaike (CAIC), Bayesian Akaike (BIC), Akaike (AIC). It has been applied to distributions to find the right distribution of the data of rainfall in the provinces of Iraq was used (maximu
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